BIOL 2153 Chapter : Microbes
Document Summary
1675: robert hooke was the first to describe microbes (fungi) 1676: antoni van leeuwenhoek was the first to describe bacteria (bacteria) 4 types of light microscopy (1)brightfield: simplest, specimen illuminated, magnified 1000x, specimen stained to increase contrast (2)phase contrast and (3)darkfield, visualize live samples, no staining required, figure 2. 5. Image contrast derived from cell structure (4)fluorescent: visualization of auto fluorescent molecules or fluorescent stains, figure 2. 6. Electron microscopes: limit of resolution 0. 2 nm 0. 4 nm (nanometers, two types of electron microscopy, transmission election microscope (tem) for observing internal cell structure, scanning election microscope (sem) for three-dimensional imaging, view surface, figure 2. 10e. Significance of being small: microorganisms are as small as 0. 2 um, size affects physiology, growth rate, and ecology, mycoplasma genitalium, high surface area-to-volume ratio aids in nutrient and waste exchange with the environment. Basic components of all microbial cells: cytoplasm, cytoplasmic membrane, ribosomes. Two structural types of cells are recognized: prokaryote and eukaryote.
